Some swimming pool structures are constructed with cleaning systems in which cleaner heads are installed in the floor and steps of the pool and direct jets of water across the inner surface of the pool to move debris collected on the inner surface toward a drain, where the debris is drawn into a circulation system for filtering. The circulation system typically includes the drain, an intake or upstream piping assembly coupled to the drain, and a pump for drawing water into the drain and through the upstream piping assembly to a filter for filtration. Filtered water is then communicated out through an outlet or downstream piping assembly to the heads installed in the floor and steps of the pool. The heads are applied to collars mounted in the floor of the pool structure in fluid communication with the piping assembly. The collars are generally installed flush with the floor of the pool.
Various manufacturers have developed several designs for cleaner heads. One commonly-used head includes a cylindrical insert carrying a piston formed with a nozzle. A guide pin extending from a sidewall of the piston navigates a sinusoidal maze on the inner surface of the insert, and as the guide pin moves through the maze in response to the flow of water through the head, the piston moves up, down, and in rotation, sequentially moving through several nozzle stations or orientations. Water applied through the head is thus directed in different directions in response to movement of the piston. This head, however, is prone to wear and breaking. The pin often snaps off, so that the piston then freely rotates within the insert without guidance. Further, as mineral deposits build up and some debris inevitably passes through the filter into the head, the maze often becomes clogged and prevents the piston from moving. The piston will thus become stuck in an up, down, or partially raised position, requiring maintenance. The piston can also become stuck when this build-up or debris becomes lodged between the piston and the insert. Further, because most pool cleaning systems are programmed to operate at night, away from the pool owner's watch, a stuck head will often go unnoticed and can cause a portion of a pool surface to remain uncleaned for a significant period of time. An improved cleaner head for in-floor pool installations is needed.